all functions in one script - javascript

I put all my .js files in one. So one page will use less than 10% of the functions there.
eg, page1.php need only .func1, but now I have func 2, 3, 4...
$(document).on("click", ".func1", function() { /* ... */ });
$(document).on("click", ".func2", function() { /* ... */ });
$(document).on("click", ".func3", function() { /* ... */ });
$(document).on("click", ".func4", function() { /* ... */ });
$(document).click(function(){ /* ... */ });
... fun20, func30.
Is it ok? I need only func1 but all this others listeners are working too. any thing I need or should do?

There's nothing wrong with your code but definitely it can get better.
There are some ways in order to do that :
1. Use a code bundler like webpack
Using webpack would be a good Idea specially for it's new feature Code Splitting that let's you to import different modules dynamically.
2. Using Modular design patterns like Revealing Module Pattern
There are someways to do this and it's so easy. I put some example codes for you down below :
// Self Invoke function
var Module1 = (function(){
// Configurations
var config = {
body : '.body',
header : '.header',
...
}
// Functions
function bodyHandler(){
...
}
function headerHandler(){
...
}
// Bind Events
$(document).on('click', config.body , bodyHandler);
$(document).on('click', config.header , headerHandler);
})()
You can separate your JavaScript code into various modules and use them in different pages.
Also you can config each module dynamically from outside (In html page for instance) like so :
(function(){
var Page = {
// Init the Module with your own configuration
init(conf){
this.config = conf;
this.bindEvents()
},
// Bind Events
bindEvents(){
$(document).on('click', this.config.body , this.bodyHandler);
$(document).on('click', this.config.header , this.headerHandler);
},
bodyHandler(){
...
},
headerHandler(){
...
},
}
// You can Init the module whereever you want
Page.init({
body : '.body',
header : '.header',
// Other options ...
})
})()

I currently have a similar process when it comes to JavaScript. All functions I write go into one large file. I then have a single function that runs when the DOM is ready that binds events onto specific elements.
By doing it that way a) I know where all the event binding is happening and b) Only events that are specific to the content of the page are actually bound
for example....
(function() {
function fnFunctionA() { ... }
function fnFunctionB() { ... }
function fnFunctionC() { ... }
$('.containerA').on('click', '.subElementA', fnFunctionA);
$('.containerB').on('click', '.subElementB', fnFunctionB);
$('.containerC').on('click', '.subElementC', fnFunctionC);
}());
Function A is only ever bound when containerA actually exists on the page and so on and so forth

Related

intercept or override javascript function of a class

I am new in javascript and jquery.
I have created a class having some functions in javascript.
My javascript class is written in a .js file.
common.js
var myGeneralClass = {
_show : function() {
console.log("showing some divs here");
},
_hide : function() {
console.log("hiding some divs here");
}
}
_show() and _hide() functions are bind to some events.
Now I have jsp file, from where final html is rendered.
myGeneralClass methods are called from various jsp files.
Some jsp script want to add some code in _show() and _hide() methods according to there need.
for eg :
employee.jsp
<script>
//want to add some lines of js code to _show() method plus its default code.
// intercept _show() method
_interceptShow : function() {
console.log("this line is custom for employee");
},
// override _show() method
_overrideShow : function() {
console.log("this line is custom for employee");
console.log("showing some divs here");
}
</script>
Can I override OR intercept methods in javascript?
Can it be possible ?
If yes then how?
For adding more code in method:
use this:
var temp = myGeneralClass._show;
myGeneralClass._show = function(){
temp();
// more code
}
for overriding:
myGeneralClass._show = function(){
// new code
}

jQuery global/local event execution order

I have a panel widget with a button. Clicking the button should execute some global actions related to all such widgets and after that execute some local actions related to this widget instance only. Global actions are binded in a separate javascript file by CSS class like this:
var App = function ()
{
var handleWidgetButton = function ()
{
$('.widgetBtn').on('click', function (e)
{
// do smth global
});
return {
init: function ()
{
handleWidgetButton();
}
};
}
}();
jQuery(document).ready(function()
{
App.init();
});
And in the html file local script is like this:
$("#widgetBtn1234").click(function (e)
{
// do smth local
});
Currently local script is executed first and global only after while I want it to be the opposite. I tried to wrap local one also with document.ready and have it run after global but that doesn't seem to change the execution order. Is there any decent way to arrange global and local jQuery bindings to the same element?
The problem you're having comes from using jQuery's .ready() function to initialize App, while you seem to have no such wrapper in your local code. Try the following instead:
var App = function ()
{
var handleWidgetButton = function ()
{
$('.widgetBtn').on('click', function (e)
{
// do smth global
});
return {
init: function ()
{
handleWidgetButton();
}
};
}
}();
$(function()
{
App.init();
});
Then in your local JS:
$(function() {
$("#widgetBtn1234").click(function (e)
{
// do smth local
});
});
Note that $(function(){}) can be used as shorthand for $(document).ready(function(){});. Also, make sure your JS file is located before your local JS, as javascript runs sequentially.
Alternatively, you can use setTimeout() to ensure everything's loaded properly:
(function executeOnReady() {
setTimeout(function() {
// Set App.isInitialized = true in your App.init() function
if (App.isInitialized) runLocalJs();
// App.init() hasn't been called yet, so re-run this function
else executeOnReady();
}, 500);
})();
function runLocalJs() {
$("#widgetBtn1234").click(function (e)
{
// do smth local
});
};
How about this instead:
var widget = $("#widgetBtn1234").get(0);//get the vanilla dom element
var globalHandler = widget.onclick; //save old click handler
// clobber the old handler with a new handler, that calls the old handler when it's done
widget.onclick = function(e){
//do smth global by calling stored handler
globalHandler(e);
//afterward do smth local
};
There might be a more jqueryish way to write this, but I hope the concept works for you.
-------VVVV----keeping old answer for posterity----VVVV--------
Why not something like this?
var App = function ()
{
var handleWidgetButton = function ()
{
$('.widgetBtn').on('click', function (e)
{
// do smth global
if(this.id === 'widgetBtn1234'){
//do specific things for this one
}
});
return {
init: function ()
{
handleWidgetButton();
}
};
}
}();
Please excuse any syntax errors I might have made as I haven't actually tested this code.
Check out my simple JQ extension I created on jsbin.
http://jsbin.com/telofesevo/edit?js,console,output
It allows to call consequentially all defined personal click handlers after a global one, handle missed handlers case if necessary and easily reset all personal handlers.

how to pass parameter in jquery using .on?

Good Day, this maybe a silly question :) how can I pass a parameter to an external javascript function using .on ?
view:
<script>
var attachedPo = 0;
$this.ready(function(){
$('.chckboxPo').on('ifChecked', addPoToBill(attachedPo));
$('.chckboxPo').on('ifUnchecked', removePoToBill(attachedPo ));
});
</script>
external script:
function addPoToBill(attachedPo){
attachedPo++;
}
function removePoToBill(attachedPo){
attachedPo--;
}
but Im getting an error! thanks for guiding :)
You need to wrap your handlers in anonymous functions:
$('.chckboxPo')
.on('ifChecked', function() {
addPoToBill(attachedPo);
})
.on('ifUnchecked', function() {
removePoToBill(attachedPo);
});
You can also chain the calls to on as they are being attached to the same element.
If your intention is to count how many boxes are checked, via passing variable indirectly to functions try using an object instead like this:
JSFiddle: http://jsfiddle.net/TrueBlueAussie/pBkhX/
var attachedPo = {
count: 0
};
$(function () {
$('.chckboxPo')
.on('change', function () {
if ($(this).is(':checked')) {
addPoToBill(attachedPo);
} else {
removePoToBill(attachedPo);
}
$("#output").prepend("" + attachedPo.count + "<br/>");
});
});
function addPoToBill(attachedPo) {
attachedPo.count++;
}
function removePoToBill(attachedPo) {
attachedPo.count--;
}
If it is not doing anything else you can simplify the whole thing to count checked checkboxes:
$(function () {
var attachedPo = 0;
$('.chckboxPo')
.on('change', function () {
attachedPo = $(".chckboxPo:checked").length;
});
});
"DOM Ready" events:
you also needed to wrap it in a ready handler like this instead of what you have now:
$(function(){
...
});
*Note: $(function(){YOUR CODE HERE}); is just a shortcut for $(document).ready(function(){YOUR CODE HERE});
You can also do the "safer version" (that ensures a locally scoped $) like this:
jQuery(function($){
...
});
This works because jQuery passes a reference to itself through as the first parameter when your "on load" anonymous function is called.
There are other variations to avoid conflicts with other libraries (not very common as most modern libs know to leave $ to jQuery nowadays). Just look up jQuery.noConflict to find out more.

jQuery and object literal function not working together

i was trying to organize my jquery code so i created an object literal, but now the focusTextArea is not working and my textarea value is not updating.
Thanks for your help.
html
<textarea id="test"></textarea>​
javascript
(function($,window,document,undefined){
var TEX = {
inputField: $("textarea#test"),
/* Init all functions */
init: function()
{
this.focusTextArea();
},
/* Function update textarea */
focusTextArea: function()
{
this.inputField.text('test');
},
}
$(document).ready(function(){
TEX.init();
});
})(jQuery,window,document);​
jsfiddle
http://jsfiddle.net/vBvZ8/1/
First of all, you haven't included jQuery correctly in the fiddle. Also, I think you mean to place the code in the head of the document (because of the document.ready handler).
More importantly perhaps the selector $("textarea#test") is run before the document is ready and therefore won't actually find the element correctly. I would recommend assigning inputField in TEX.init:
(function($,window,document,undefined){
var TEX = {
/* Init all functions */
init: function()
{
this.inputField = $("#test");
this.focusTextArea();
},
/* Function update textarea */
focusTextArea: function()
{
this.inputField.text('test');
},
}
$(document).ready(function(){
TEX.init();
});
})(jQuery,window,document);​
Updated example: http://jsfiddle.net/xntA2/1/
As a side note, textarea#test should be changed to just #test. The textarea bit is superfluous since there should be only one element on the page with id=test.
Alternative syntax to avoid looking for an element before it exists is to return the element from a function:
(function($,window,document,undefined){
var TEX = {
/* function won't look for element until called*/
inputField:function(){
return $("textarea#test")
},
init: function()
{
this.focusTextArea();
},
focusTextArea: function()
{
this.inputField().text('test');
},
}
$(document).ready(function(){
TEX.init();
});
})(jQuery,window,document);
DEMO: http://jsfiddle.net/vBvZ8/5/
I realize this is a simplified example...but you are also very close to creating a jQuery plugin and that may also be of benefit. Following provides same functionality as example:
(function($, window, document, undefined) {
$.fn.focusTextArea = function() {
return this.each(function(){
$(this).text('test');
})
};
})(jQuery, window, document);
$(function() {
$('textarea').focusTextArea()
});
DEMO: http://jsfiddle.net/vBvZ8/8/

Event object eaten by jQuery animation callback

I have a problem with event object passed to the function in drop event. In my code, div#dropArea has it's drop event handled by firstDrop function which does some animations and then calls the proper function dropFromDesktop which handles the e.dataTransfer.files object. I need this approach in two separate functions because the latter is also used further by some other divs in the HTML document (no need to duplicate the code). First one is used only once, to hide some 'welcome' texts.
Generally, this mechanism lets you drag files from desktop and drop them into an area on my website.
Here's, how it looks (in a shortcut):
function firstDrop(ev) {
var $this = $(this);
//when I call the function here, it passes the event with files inside it
//dropFromDesktop.call($this, ev);
$this.children('.welcomeText').animate({
opacity: '0',
height: '0'
}, 700, function() {
$('#raw .menu').first().slideDown('fast', function() {
//when I call the function here, it passes the event, but 'files' object is empty
dropFromDesktop.call($this, ev);
});
});
}
function dropFromDesktop(ev) {
var files = ev.originalEvent.dataTransfer.files;
(...) //handling the files
}
$('#dropArea').one('drop', firstDrop);
$('some_other_div').on('drop', dropFromDesktop);
The problem is somewhere in jQuery.animation's callback - when I call my function inside it, the event object is passed correctly, but files object from dataTransfer is empty!
Whole script is put inside $(document).ready(function() { ... }); so the order of function declarations doesn't matter, I guess.
I suspect your problem is related with the lifetime of the Event object. Unfortunately, I have no clue about the cause of it. But, there is a way to workaround it that I can think of and it is keeping a reference to Event.dataTransfer.files instead.
var handleFileList = function(fn) {
return function(evt) {
evt.preventDefault();
return fn.call(this, evt.originalEvent.dataTransfer.files);
};
};
var firstDrop = function(fileList) { ... }
var dropFromDesktop = function(fileList) { ... }
$('#dropArea').one('drop', handleFileList(firstDrop));
$('some_other_div').on('drop', handleFileList(dropFromDesktop));​

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